GEG-1 Lecture Notes - Lecture 23: Kilogram, Metric System, Electromagnetic Radiation
Document Summary
Electromagnetic radiation- given off by all bodies, travels in waves. Travels in waves, determined by size of wave. Wavelength- distance from the crest of one wave to the crest of next one. Infrared- red, orange, yellow, green, blue, blue, violet. Color determined by wavelength reflected of another. Blackbody- follows these laws perfectly (earth, sun). First law- amount of energy in universe is constant- energy cannot be created or destroyed. Second law- no conversion of energy is 100% efficient; some is lost as heat. Entropy- amount of disorder in a system. Can decrease entropy (more order) in one place only by increasing it somewhere else (less order). Open, closed systems: can decrease entropy with inputs from outside. Metric system- outgrowth of french revolution; sought a more rational society. International system of units (si)- version of metric system giving official units for science and commerce. Derived units- all other units come from units ex. (area is m squared, speed is m/s)
